Detection and Characterization of Airborne Microplastics in Industrial and Landfill Regions of Ankara (Türkiye) Using Xanthoria parietina (L.) Th. Fr.

Despite being a recently recognized environmental concern, the terrestrial dispersion of airborne microplastics (MPs) pollution remains uncertain. This study investigates airborne microplastic contamination in industrial zones and a landfill area of Ankara (Türkiye) using the epiphytic lichen Xanthoria parietina (L.) Th. Fr. as a passive bioindicator. Lichen samples were collected from three organized industrial zones, a municipal landfill. Microplastics were extracted using a modified wet peroxide oxidation method and characterized by stereomicroscopy, Rose Bengal staining, and Fourier Transform Infrared (FT-IR) spectroscopy. A total of 566 microplastic particles were identified, predominantly as microfibers, indicating strong contributions from textile-related and industrial sources. Microplastic abundance and density varied markedly among sites, with the highest levels observed at Sincan Organized Industrial Zone, followed by Ostim Organized Industrial Zone, the landfill site, and Polatlı Organized Industrial Zone. FT-IR analysis revealed a diverse polymer assemblage, including PE, PP, PET, PS, PVC, PA, PAN, PC, PMMA, PU, and PTFE. Although microplastics were also detected at reference lichen (Evernia prunastri (L.) Ach.), their lower abundance and reduced polymer diversity suggest background deposition and possible long-range atmospheric transport. These findings demonstrate the influence of industrial activity and waste-related sources on airborne microplastic contamination and confirm X. parietina as a suitable bioindicator for atmospheric microplastic biomonitoring.